Hole punching devices for recording media



Nov. 18, 1969 EK ETAL 3,478,629

HOLE PUNCHING DEVICES FOR RECORDING MEDIA Filed May 1, 1967 2Sheets-Sheet 1 4 M/I/F/VTOES mean Hi/Vf/K 5K Jwm gum/5e WA/rie :rzwwpNov. 18, 1969 B. H. EK EFAL HOLE PUNCHING DEVICES FOR RECORDING MEDIA .2Sheets-Sheet 3 Filed May 1, 1967 United States Patent 9 Claims ABSTRACTOF THE DISCLOSURE This invention relates to hole punching devices forpunch tapes and similar recording media and has for an object theprovision of a punch head in which a plurality of punches 21 arecombined in a rigid yet easily interchangeable way with a punch die 17and punch guide means 14. The punch guide means are formed as a barhaving a cylindrical shank portion 12 fitted into a base member andadjustable angularly and longitudinally therein. The punches 21 aremounted for longitudinal displacement within transversal holes drilledin said punch guide 14 employing the overhanging rod-shaped punch die 17mounted in said punch head 12, 14 as a drill jig. The upper ends of thepunches 21 are connected to bell cranks 27 actuated by push rods 29 froma drive mechanism known in itself, and this connection is establishedand disestablished by turning the punch head shank 12 relative to thebase member 10.

This invention relates to hole punching devices and the like apparatusfor punch cards, punch tapes and similar recording media.

In known hole punching apparatus for punch tapes the "ice work is madewhen manufacturing the punch head which is delivered as an exchangeableunit which can be mounted by servicing personnel without any specialequipment or training.

The improved punch head comprises a punch die, a plurality of punchesfor engaging punch holes in the die and punch guides, and according tothe invention the punch guides and punch die are rigidly combined to anexchangeable unit provided with a cylindrical shank member which issupported by a base member and is angularly as well as longitudinallyadjustable therein.

The invention will be described more in detail with reference to theannexed drawings, wherein FIG. 1 is a fragmentary elevation view of apunch head as seen from the side wherefrom the tape is inserted,

FIG. 2 is a somewhat diagrammatical cross section view along A--A inFIG. 1,

FIG. 3 is a top plan view of a punch die, and

FIGS. 4 and 5 is an elevation view and end view, respectively, of asecond embodiment of the principal parts of a punch head.

In FIG. 1 numeral 10 denotes a base member which is preferably shaped asa thick plate. This plate 10 has punching mechanism is supported by arigid base memher, most often made of cast iron. The punch die whichmust be made of a wear-resistant material, usually hardened steel, formsas a rule a separate unit that is mounted on the base member. The sameapplies to the punch guides which must be machined to close tolerancesto prevent the punches from striking against the hole walls of the die.The fitting of the punch guides and the punch die in the base istherefore an expensive operation. Since the punches, the punch guidesand the die belong to those components subjected to the heaviest wear itis desirable that they can be exchanged swiftly and without muchfitting. This is not possible in most punching devices commerciallyavailable at present.

It has been proposed to improve the interchangeability of componentssubjected to wear by forming the die and the punch guides in separatecomponents provided with guide =bores which fit accurately around twoclosely ma chined guide columns. Distance pieces are also mounted atthose columns, to provide a channel for the tape.

To attain complete interchangeability the said components must bemachined to very close tolerances, and the replacement of parts is acomparatively tedious operation, as a great number of components shallbe changed and assembled in a certain order. Another limitation imposedby this construction is that the tape must be inserted through the punchhead which complicates handling. Moreover, the punching device cannot beused for punching the edges of cards, as this requires the punching areato be accessible laterally.

The present invention has for its object the provision of a punch headwithout these drawbacks. This punch head is easily exchangeable byloosening a single screw, and the punch die as well as the punches andpunch guides are removed in a single operation. All precision acylindrical bore 11 therein receiving a shank portion 12 of a punch headunit 14 which is angularly and longitudinally adjustable within the saidbore. The punch head shank 12 is secured axially and radially by a setscrew 13. The punch head 14 extends beyond the base member 10 and hasits cross section shaped like a segment of a circle and acts as a punchguide. The punch head is preferably made of a material suited forguiding the punches which are made of steel or the like, such as brassor auto-lubricating bronze. If the punch head 14 is not made of aself-lubricating material it is preferably formed with an axial bore 15which is filled with a lubricant.

Parallel to the flat underside 16 of the punch head 14 a cylindricalpunch die 17 is rigidly mounted in a bore 18 in the cylindrical shank12. The spacing between the highest portion of the die 17 and the flatbottom surface 16 0f the punch head is determined by the thickness ofthe medium to be punched. Before the die is rigidly secured in the bore18 punch holes 19 are drilled therein, corresponding in FIG. 3 to an8-channel punch tape. The holes are drilled with clearance downwards toprevent the punched-out matter to stick. If the die shall be hardenedthis is also effected before its mounting in the punch head, of course.

The punch die now is used as a drill jig for drilling the guide holes 20in the punch head, to ensure that the latter will become accuratelyaligned with those in the die. The fitting of the die 17 in the bore 18need not be made with any too great accuracy, as a minor deviation ofthe die holes from 'being perpendicular to the surface 16 is of noimportance. 'By turning the punch head relative to the bore 11 anypossible oblique position of the punches rela-' tive to the punch drivemechanism will be readily compensated.

After the bores in the die and punch head have been machined to theirfinal measure and smoothness the punches 21 are mounted in the holes 20and the punch head can be inserted by its shank 12 in the bore 11 inplate 10. During this operation the punch head is turned in such a waythat the punches coincide for example with the plane indicated at 22 inFIG. 1. When in the correct axial position the punch head is turnedclockwise until a milled-down portion 23 near the top of each punchengages a slot 24 in a bell crank 27 transmitting the drive to thepunch. The top portion of the latter is received in a transverse slot inthe bell crank 27. All bell cranks are supported by a common axle 28 andare actuated by push rods 29 engaging recesses 29a in the bell cranks.The push rods 29 are actuated individually in any known or suitablemanner, for example by electromagnets (not illustrated). When a push rod29 is moved to the left in FIG. 1, its associated bell crank 27 urgesthe punch 21 downwards, and a hole is punched in the recording medium.On return of the bell crank the punch is pulled back into initialposition. To prevent the overhangingdie 17 from giving way duringpunching two supporting pads 30, 31 are provided. These pads are shapedwith oblique sides 32 defining a chute for the punched-out matter. Thepads 30, 31 are secured to the base member 10.by means of screws 33, anda plate 34 is mounted 'as a cover at their outer face.

Since one end of the dies 17 is free a punch tape can be insertedlaterally into the space 35 between the punch head and the die. This iseifected much faster than threading the tape through a gap closed atboth sides.

Exchange of separate punches as well as of the complete punch head iseasily effected in the embodiment illustrated. By loosening the setscrew 13 the whole unit can be turned within the bore 11 to release thepunches from their? engagement with the bell cranks 27. Any of thepunches may be extracted from the punch head to be replaced by a newone. If the pads 30, 31 are removed the complete punch head may beexchanged by a simple operation.

A worn punch head may simply be scrapped, as it is much less expensiveto manufacture than earlier known punch heads of a comparable quality.

It is possible to recondition a worn punching device by machining thebores in the punch guide and die to a slightly greater diameter. Thepunches are then replaced by new ones having a greater diameter. Thereconditioning can be effected without further dismounting and istherefore very inexpensive.

In the modified embodiment illustrated in FIGS. 4 and 5 the punch headis made of a steel cylinder 35 with an axial, eccentrically offset bore36. The cylinder 35 further has an axial slit 38 for guiding therecording tape through the punch head. The slit partly intersects thebore 36. The distance between the bottom 39 of the slit and thecircumference of the bore 36 corresponds to the thickness of the mediumto be punched. The portion 40 of the cylinder disposed below the slitprovides the punch die and has holes 19 machined therein like the dieillustrated in FIG. 3. Also the wall of the cylinder 35 above the bore36 is formed with corresponding holes with a greater diameter than thoseof the die. After the cylinder has been hardened, a hollow bush 37 ofbronze or similar material is forced into the bore 36, and holes aredrilled through the walls of the bush 37, using the die as a drill jig.After machining the drilled holes to final measures and smoothness thepunches are mounted in the holes. The bush 37 acts as a punch guide, andits hollow interior is preferably filled with a lubricant. The bush maybe made of a self-lubricating bronze or the like, instead, which makesspecial oil channels unnecessary.

This punch head is mounted in the same way as the first one describedabove, by inserting the cylindrical shank portion41 into the bore in thebase member 11.

What we claim is:

1. A hole punching device for punch tapes, punch cards and the likerecording media, comprising a punch die, a plurality -of punches andguide means for the punches, wherein the said punch guide means, thepunches and the punch die are combined in an exchangeable punch headwhich is provided with a cylindrical shank portion mounted with angularand longitudinal adjustability in a base member.

2. A hole punching device as claimed in claim 1, wherein the punch headis shaped as a straight circular cylinder having a recess extendingparallel to the cylinder axis at least in the part thereof beyond theshank portion.

3. A hole punching device as claimed in claim 2, wherein the said recessincludes a cylindrical segment,

. said punch die comprising an elongated, substantially cylindricalportion disposed within said recess parallel to the cylinder axis.

4. A hole punching device as claimed in claim 3, wherein saidcylindrical segment is formed of bronze, said die being formed withholes for receiving said punches.

5. A hole punching device as claimed in claim 4, wherein said punchguide is formed with an axial bore containing a lubricant.

6. A hole punching device as claimed in claim 2, wherein said cylinderis made of a material suitable for a punch die, such as steel, andwherein said recess is formed as a bore parallel to the cylinder axis,an axial slit having one limiting surface intersecting the circumferenceof the bore is machined from the free end of the cylinder to a depthcorresponding to the width of the recording medium support, the heightof the slit being greater than the thickness of the said recordingmedium support, and a bush of a material suited as a guide for thepunches is inserted into said bore.

7. A hole punching device as claimed in claim 6, wherein holes for thepunches are drilled diametrically through the cylinder and the bushperpendicularly to said slit.

8. A hole punching device as claimed in claim 7, wherein said bush isprovided with a channel for the lubricant traversed by the punches.

9. A hole punching device as claimed in claim 8, wherein portions of thepunches are disconnected from said drive means upon angular displacementof the punch head.

References Cited UNITED STATES PATENTS 2,325,437 8/1943 Temple 83622 XWILLIAM S. LAWSON, Primary Examiner U.S. Cl. X.R.

